#include <iostream>
#include <string>
#include <cstdlib>

using namespace std;

struct student
{
	int id;
	int &score; // 引用成员，必须在初始化时绑定
};
int main(int argc, char const *argv[])
{

	int grade = 100;
	student s1 = {1, grade}; // 等价于 int &scoer=grade;

	grade = 20;
	cout << s1.score << endl;

	s1.score = 123;
	cout << grade << endl;

	return 0;
}
